1. Field of the Invention
The present invention relates to an optical encoder that receives light emitted from a light source by a photo detector and detects the light received by the photo detector.
2. Description of Related Art
An optical encoder that receives light emitted from a plurality of light sources by photo detectors provided for each of the light sources has been known (see, for instance, JP-A-5-99691 (Page 3 and FIG. 1)).
The optical encoder described in JP-A-5-99691 includes: a code plate on which slits and light shield sections are alternately arranged at a predetermined pitch; a pair of light sources disposed on a front side of the code plate; and a pair of light receiving arrays disposed on a rear side of the code plate that respectively receive light emitted from the pair of light sources. In the optical encoder, the light sources and the light receiving arrays are respectively opposed sandwiching the code plate disposed therebetween.
In existing encoders such as the above-mentioned optical encoder, when the pair of light sources or the pair of light receiving arrays are disposed too close to each other, the light emitted from one of the light sources enters not only the opposing light receiving array but also the other light receiving array, thus causing crosstalk.